Certification Exams

Waterworks Operator Certification Exam

Note: We are updating our Waterworks operator certification application process. The online certification application process will close at 5 p.m. January 5, 2024. Please check back January 16, 2024, for instructions on the new Waterworks operator certification application process.

PLEASE NOTE: Any waterworks certification applications received after close of business on Thursdays will be processed the following week.

Welcome to the Waterworks Operator Certification exam page. Please select what you're looking for:

Operator Certification Exam Application

To apply for a Waterworks Operator Certification exam:

  1. You must have a valid email address.
  2. You must be registered with Secure Access Washington (SAW). Instructions for registering with SAW (PDF).
  3. Once registered for SAW, go to the login page at secureaccess.wa.gov/myAccess/saw/select.do.
  4. Enter your credentials and select:
    • “Add a New Service” (in red);
    • “Browse List of Services”;
    • “Department of Health” ; and
    • “Apply” for the “Waterworks Operator Certification” category.
  5. Please read all instructions carefully.

Tips to filling out the online certification application (Word)

Types of Waterworks Certification Applications

Certification Exam

Almost all public drinking water systems are required to have a certified waterworks operator in responsible charge of the water system. Candidates that meet the requirements of WAC 246-292-060 are eligible to take an exam to become a certified operator.

Operator-in-Training (OIT) Exam

Allows candidates to sit for a Waterworks certification exam prior to having completed all required water system operating experience. Candidates must meet the eligibility requirements in WAC 246-292-060(3).

Upgrade without Exam

A certified “Operator-in-Training” (OIT) may apply to become fully certified once they've obtained the required water system operational or water treatment experience.


We may issue an operator certification without an exam to applicants who hold valid water system operator certifications issued by another state or province (WAC 246-292-075) and if they meet the following criteria:

  • The other certification program's minimum education, operating experience, and professional growth requirements must be equal to or more stringent than Washington state.
  • The applicant has passed the appropriate level Association of Boards of Certification (ABC) exam, and;
  • Applicant is currently certified in the originating state.

To request further information on reciprocity with Washington, please contact our certification program at: dwopcert@doh.wa.gov.

Temporary Certification

We may issue a nonrenewable temporary certification to an individual to fill a vacated position on a public water system. Temporary certification is contingent on the requirements in WAC 246-292-080.

Study Materials

The Association of Boards of Certification (ABC) develops all Waterworks operator certification exams for Washington.

Here are study guides developed by ABC for the Water Distribution and Water Treatment Plant operator certification exams.

PSI/AMP Very Small Water System Operator Practice Exam

The American Water Works Association (AWWA) and Water Environment Foundation (WEF) worked with ABC to also develop study guides based on the core competencies in the ABC exams:

Cross Connection Control Specialist (CCS)

The CCS exam is specific to Washington State. There are several sources of study materials.

Backflow Assembly Tester (BAT)

Washington Certification Services (WCS) administers our BAT program. You can access WCS's Backflow Assembly Tester Program.

Publications and Resources